Fan positioning structure

ABSTRACT

A fan positioning structure includes a base, a cover, and a fan. Through configuring a rotating shaft of the fan, one end of the fan presses against a stopping portion of the base, and the other end of the fan bears against a stopper of the cover, such that the fan is confined to stably rotating between the base and the cover.

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No(s). 097217359 filed in Taiwan, R.O.C. on Sep. 25, 2008, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a positioning structure, and more particularly to a fan positioning structure.

2. Related Art

With the progress of technologies and the rapid development of electronic industry, the operating speed of an electronic device such as a computer, a personal digital assistant (PDA), or a global positioning system (GPS) is greatly increased. However, due to the increasingly high operating speed, the electronic device generates more heat during operation. If the heat cannot be effectively released, once the maximum load of the electronic device is exceeded, the electronic device fails.

In order to solve the heat-dissipation problem of the electronic device, a heat-dissipation fan is commonly disposed on heat-generating elements (for example, chips, a central processing unit (CPU), or integrated circuits (ICs)) of the electronic device, such that the heat-dissipation fan operates to generate an air flow to enable the heat-generating elements to maintain their operational efficiencies within a certain temperature range. Meanwhile, considering the manufacturing cost of the heat-dissipation fan, currently, a heat-dissipation fan with a self-lubricating bearing is usually used.

In such a heat-dissipation fan with a self-lubricating bearing, the rotation of a fan rotor is supported by a rotating shaft pivoted in a sleeve bearing, and after the fan is assembled, a C-shaped snap ring is snapped at one end of the rotating shaft from a bottom portion of the bearing sleeve, so as to prevent the fan blades from detaching from the bearing during rotation due to the centrifugal force. Meanwhile, in order to prevent the fan blades from abrading the axle seat of the fan blades and the C-shaped snap ring at the end of the rotating shaft during operation, a gap needs to be maintained with respect to the upper and lower ends of the bearing. However, due to the gap, the rotating shaft cannot rest on a fixed support. After the fan operates for a long period of time, the friction force between the rotating shaft and the C-shaped snap ring may become too large, so that the C-shaped snap ring is easily worn out or even loosened due to elastic fatigue, and the rotating shaft cannot be fixed. As a result, the fan blades easily moves up and down, sways, and generates noises during rotation, thus reducing the service life of the heat-dissipation fan.

In addition, such a heat-dissipation fan may be applied in a portable electronic device such as a PDA. Since the portable electronic device is mainly characterized by a light weight, thin structure, and portability, the using status of the portable electronic device is frequently changed according to different operating environments. For example, the portable electronic device may be changed from a horizontal operation direction to a vertical operation direction, or horizontally inverted during operation. At this time, if the C-shaped snap ring is loosened, the fan blades may move up and down. In this case, not only large noises are generated, but also the electronic device even vibrates with the movement of the fan, thereby causing troubles for a user in operating the electronic device. What's worse, the consumers are likely to consider this problem as a product defect, which damages the reputation of the manufacturer.

Moreover, a frame of a conventional heat-dissipation fan includes a frame body, a motor seat, and a plurality of ribs. The frame body has a plurality of bumps. Two ends of each rib are connected to the motor seat and one of the bumps respectively. In order to prevent the bumps from blocking an air flow field generated when the fan operates, the bumps are often designed to have an area only slightly larger than that of the ribs, resulting in poor connection strength thereof. Meanwhile, each bump also has a tip. When the fan operates, the air flow passing through the bumps is affected by the tips, such that the air flow field may be separated and a turbulence phenomenon occurs. Due to the turbulence phenomenon, not only the air flow is influenced and the wind shear effect occurs, but also noises are generated by the air flow, and the heat-dissipation performance is deteriorated.

SUMMARY OF THE INVENTION

In view of the above problems, the present invention is a fan positioning structure, which is applicable to solve the problems that a C-shaped snap ring sleeved on a rotating shaft for stabilizing a rotation of the rotating shaft is deformed during the operation of a fan and meanwhile the rotating shaft moves up and down within a bearing and drives the fan to move within a frame of the fan, thereby preventing the rotating shaft or the bearing from being excessively abraded and further preventing the generation of noises.

The present invention provides a fan positioning structure, which comprises a base, a cover, and a fan. The base comprises a stopping portion. The cover is fitted to the base, and comprises a stopper corresponding to the stopping portion of the base. The fan is rotatably disposed between the base and the cover, and comprises a rotating shaft penetrating the fan. One end of the rotating shaft presses against the stopping portion of the base, and the other end of the rotating shaft bears against the stopper of the cover, such that the fan is confined to rotating between the base and the cover.

In addition, the present invention further provides a fan positioning structure, which comprises a base, a cover, and a fan. The base comprises a stopping portion. The cover is fitted to the base, and comprises a stopper corresponding to the stopping portion of the base. The fan is rotatably disposed between the base and the cover, and comprises an urging portion and a rotating shaft. The urging portion and the rotating shaft are disposed on two opposite sides of the fan. The urging portion bears against the stopper of the cover, and one end of the rotating shaft contrary to the fan presses against the stopping portion of the base, such that the fan is confined to rotating between the base and the cover.

In the fan positioning structure of the present invention, the rotating shaft or the urging portion disposed at the fan presses against the stopper disposed on the cover, such that the fan is confined between the base and the cover. Therefore, the fan cannot move in an axial direction of the rotating shaft between the base and the cover during operation, thereby avoiding the abrading phenomenon between the rotating shaft and the bearing, and effectively solving the noise generation problem caused by the movement of the fan between the base and the cover.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given herein below for illustration only, and thus is not limitative of the present invention, and wherein:

FIG. 1 is a schematic exploded view of a first embodiment of the present invention;

FIG. 2 is a schematic assembled view of the first embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view of the first embodiment of the present invention;

FIG. 4 is a schematic view of operations of the first embodiment of the present invention;

FIG. 5 is a schematic exploded view of a second embodiment of the present invention;

FIG. 6 is a schematic cross-sectional view of the second embodiment of the present invention; and

FIG. 7 is a schematic assembled view of a third embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The fan positioning structure of the present invention is applicable to heat-dissipation structures of electronic devices such as a display card chipset, a memory module, a mobile phone, a PDA, and a hard-disk digital video camera. The above illustration is merely taken as examples, and the present invention is not limited thereto.

FIG. 1 is a schematic exploded view of a first embodiment of the present invention. A fan positioning structure according to the first embodiment of the present invention comprises a base 10, a cover 20, and a fan 30. The base 10 has an accommodating space 11, and comprises a stopping portion 12, a bearing 13, and a stator 14 disposed on one end thereof. The bearing 13 is disposed above the stopping portion 12 and formed with a shaft hole 131, such that the stopping portion 12 is partially exposed out of the shaft hole 131. The stator 14 has an opening 141 and is sleeved on the bearing 13 through the opening 141. Meanwhile, a plurality of blocks 15 and a plurality of rabbets 16 are disposed on the other side of the base 10 opposite to the accommodating space 11. The cover 20 comprises a stopper 21, a connecting rib 22, and a frame 25. The stopper 21 is positioned corresponding to the stopping portion 12 of the base 10, and is connected to the frame 25 through the connecting rib 22. The connecting rib 22 is disposed in a wave-shaped manner. A plurality of fasteners 23 and inserts 24 is disposed on side edges of the cover 20. The fasteners 23 and the inserts 24 are respectively corresponding to the blocks 15 and the rabbets 16 of the base 10. The fan 30 comprises a rotating shaft 31 and a rotor 32. The rotor 32 has a through hole 321, such that the rotating shaft 31 is enabled to penetrate the rotor 32 through the through hole 321. The stator 14 and the rotor 32 belong to the prior art, and are not technical features of the present invention, so detailed structures thereof are not described herein again.

FIG. 2 is a schematic assembled view of the first embodiment of the present invention, and FIG. 3 is a schematic cross-sectional view of the first embodiment of the present invention. According to the first embodiment of the present invention, one end of the rotating shaft 31 of the fan 30 penetrates the shaft hole 131 of the bearing 13, and presses against the stopping portion 12 of the base 10, such that the rotor 32 of the fan 30 is located above the stator 14 of the base 10, and the fan 30 rotates within the accommodating space 11 of the base 10. Then, the fasteners 23 and the inserts 24 disposed on the edges of the cover 20 are correspondingly fastened to the blocks 15 of the base 10 and embedded into the rabbets 16 of the base 10, such that the cover 20 is stably fitted to the base 10. At this time, the stopper 21 on the cover 20 contacts one end of the rotating shaft 31 of the fan 30 opposite to the stopping portion 12. Thus, one end of the rotating shaft 31 presses against the stopping portion 12 of the base 10, and the other end of the rotating shaft 31 bears against the stopper 21 of the cover 20, such that the fan 30 is confined to stably rotating between the base 10 and the cover 20 within the accommodating space 11, and the fan 30 cannot move in an axial direction of the rotating shaft 31 between the base 10 and the cover 20 during rotation.

Meanwhile, if the fan positioning structure according to the first embodiment of the present invention is inverted, for example, horizontally inverted, as shown in FIG. 4, since the fan 30 is confined between the base 10 and the cover 20 by the rotating shaft 31, the fan 30 can maintain a relative position between the cover 20 and the base 10 even if the fan positioning structure is inverted by different angles, thereby effectively preventing the fan 30 from moving axially between the cover 20 and the base 10 when being inverted by different angles.

Moreover, referring to FIGS. 1 and 2 again, the connecting rib 22 on the cover 20 is disposed in a wave-shaped manner and connects the stopper 21 with the frame 25. When the fan 30 rotates, ambient air is driven to form a vertical air flow that enters the accommodating space 11 from the base 10 and is discharged out of the accommodating space 11 from the cover 20. When the air flow is discharged from the cover 20, the air flow is linearly guided by the wave-shaped connecting rib 22, such that the discharged air flow does not generate air turbulence between the fan 30 and the cover 20 or on an outer surface of the cover 20 opposite to the base 10, so as to generate a fluent pneumatics effect, thereby effectively reducing the turbulence phenomenon, wind shear effect, and noises.

FIG. 5 is a schematic exploded view of a second embodiment of the present invention, and FIG. 6 is a schematic cross-sectional view of the second embodiment of the present invention. The second embodiment of the present invention has approximately the same structure as the first embodiment, so only the difference between the two embodiments is illustrated below. In a fan positioning structure according to the second embodiment of the present invention, the fan 30 comprises an urging portion 322, a notch 323, a rotating shaft 31, and a rotor 32. The urging portion 322 and the notch 323 are respectively disposed on two opposite sides of the rotor 32. One end of the rotating shaft 31 penetrates into the notch 323. The urging portion 322 of the fan 30 bears against the stopper 21 of the cover 20. The other end of the rotating shaft 31 that does not penetrate into the notch 323 penetrates the shaft hole 131 of the bearing 13, and presses against the stopping portion 12 of the base 10. Thus, the fan 30 is confined to rotating between the base 10 and the cover 20, thereby preventing the fan 30 from making a reciprocating axial movement between the base 10 and the cover 20.

FIG. 7 is a schematic assembled view of a third embodiment of the present invention. The third embodiment of the present invention has approximately the same structure as the second embodiment, so only the difference between the two embodiments is illustrated below. In a fan positioning structure according to the third embodiment of the present invention, the accommodating space 11 is disposed in the cover 20, and an air vent 18 in communication with the exterior is opened on a side wall 17 of the accommodating space 11. The stopper 21 of the cover 20 comprises a bump 211. The bump 211 is disposed on one side of the stopper 21 facing the fan 30. When the cover 20 is fitted to the base 10, the bump 211 on the stopper 21 of the cover 20 presses against the urging portion 322 of the fan 30, such that the fan 30 is confined between the base 10 and the cover 20. According to the first embodiment and the second embodiment, when the fan 30 rotates, ambient air is driven to form a vertical air flow that enters the accommodating space 11 from the base 10 and is discharged out of the accommodating space 11 from the cover 20. According to the third embodiment of the present invention, when the fan 30 rotates, an air flow in a horizontal flowing direction is generated, which enters the accommodating space 11 from the cover 20 and is discharged out of the accommodating space 11 from the air vent 18.

Therefore, the fan positioning structure of the present invention is applicable to both fans for generating a vertical air flow and fans for generating a horizontal air flow.

In the fan positioning structure of the present invention, by disposing the rotating shaft of the fan or by combining the rotating shaft with the urging portion, two ends of the fan respectively press against the stopping portion of the base and bear against the stopper of the cover, such that the fan is confined to rotating between the base and the cover. Thus, the reciprocating movement of the fan in the axial direction of the rotating shaft between the base and the cover can be avoided without disposing any C-shaped snap ring, and the abrasion between the rotating shaft and the bearing is reduced, so as to enable the rotating shaft to stably rotate within the bearing, thereby solving the noise generation problem when the fan rotates.

Meanwhile, the wave-shaped connecting rib disposed on the cover generates a fluent pneumatics effect, thereby effectively reducing the turbulence phenomenon, wind shear effect, and noises. 

1. A fan positioning structure, comprising: a base, comprising a stopping portion; a cover, fitted to the base, and comprising a stopper corresponding to the stopping portion; and a fan, rotatably disposed between the base and the cover, and comprising a rotating shaft penetrating the fan; wherein one end of the rotating shaft presses against the stopping portion, and the other end of the rotating shaft bears against the stopper, such that the fan is confined to rotating between the base and the cover.
 2. The fan positioning structure according to claim 1, wherein the stopper comprises a bump, and the bump is disposed on one side of the stopper facing the fan and presses against the rotating shaft of the fan.
 3. The fan positioning structure according to claim 1, wherein the cover further comprises a frame and a connecting rib, the frame is fitted to the base, and the connecting rib connects the frame with the stopper.
 4. The fan positioning structure according to claim 3, wherein the connecting rib is wave-shaped.
 5. The fan positioning structure according to claim 1, wherein the base further comprises a bearing and a stator, the bearing is disposed on one end of the base where the stopping portion is disposed, the stator is sleeved on the bearing, and the fan further comprises a rotor for electrically interacting with the stator.
 6. A fan positioning structure, comprising: a base, comprising a stopping portion; a cover, fitted to the base, and comprising a stopper corresponding to the stopping portion; and a fan, rotatably disposed between the base and the cover, and comprising an urging portion and a rotating shaft disposed on two opposite sides thereof; wherein the urging portion bears against the stopper, and one end of the rotating shaft contrary to the fan presses against the stopping portion, such that the fan is confined to rotating between the base and the cover.
 7. The fan positioning structure according to claim 6, wherein the stopper comprises a bump, and the bump is disposed on one side of the stopper facing the fan and presses against the urging portion of the fan.
 8. The fan positioning structure according to claim 6, wherein the cover further comprises a frame and a connecting rib, the frame is fitted to the base, and the connecting rib connects the frame with the stopper.
 9. The fan positioning structure according to claim 8, wherein the connecting rib is wave-shaped.
 10. The fan positioning structure according to claim 6, wherein the base further comprises a bearing and a stator, the bearing is disposed on one end of the base where the stopping portion is disposed, the stator is sleeved on the bearing, and the fan further comprises a rotor for electrically interacting with the stator. 